Adaptive audio signal filtering

ABSTRACT

An apparatus comprising: an audio signal analyser configured to analyse an audio signal; an audio signal processor configured to signal process the audio signal to enhance the speech component of the audio signal dependent on determining the audio signal comprises speech components; and signal processing the audio signal to enhance a loudness of the audio signal otherwise.

FIELD

The present application relates to adaptive audio processing, and inparticular, but not exclusively to an adaptive audio processing for usein portable apparatus.

BACKGROUND

The use of electro-dynamic loudspeakers or earpiece units in apparatusis common. Most electronic devices contain an electro dynamicloudspeaker or transducer configured to convert electrical signals intoacoustic waves to be output and heard by the user of the apparatus. Forexample mobile or similar telephones can contain an integratedtransducer sometimes called an integrated handsfree (IHF) transducerconfigured to operate as an earpiece for speech and also as aloudspeaker for hands free and audio signal playback.

SUMMARY

Embodiments attempt to address the above problem.

There is provided according to a first aspect a method comprising:analysing an audio signal comprises speech components; signal processingthe audio signal using a first one or more parameter to enhance thespeech component of the audio signal dependent on determining the audiosignal comprises speech components; and signal processing the audiosignal using a second one or more parameter to enhance the audio signalotherwise.

Signal processing the audio signal to enhance the speech component ofthe audio signal using a first one or more parameter dependent ondetermining the audio signal comprises speech components may comprise:filtering the audio signal into at least two bands; performing a dynamicrange control processing on the at least two bands according to thefirst one or more parameter, the first one or more parameter being afirst set of dynamic range control settings so to enhance anintelligibility of the speech component of the audio signal; andcombining the dynamic range control processed bands into an output audiosignal.

Performing a dynamic range control processing on the at least two bandsmay comprise compressing a mid-band frequency range compared to thehigher-band frequency range.

Signal processing the audio signal using a first one or more parameterto enhance the speech component of the audio signal dependent ondetermining the audio signal comprises speech components may comprise atleast one of: equalising the audio signal to enhance an intelligibilityof the speech component of the audio signal; and filtering the audiosignal to enhance an intelligibility of the speech component of theaudio signal.

Signal processing the audio signal using the second one or moreparameter to enhance the audio signal may comprise: filtering audiosignal into at least two bands; performing a dynamic range controlprocessing on the audio signal at least two bands according to thesecond one or more parameter, the second one or more parameter being asecond set of dynamic range control settings so to enhance a loudness ofthe audio signal; and combining the dynamic range control processedbands into an output audio signal.

Performing a dynamic range control processing on the audio signal atleast two bands according to a second set of dynamic range controlsettings may comprise compressing a higher-band frequency range comparedto the mid-band frequency range.

Signal processing the audio signal using the second one or moreparameter to enhance the loudness of the audio signal may comprise atleast one of: equalising the audio signal using the second one or moreparameter to enhance the loudness of the audio signal; and filtering theaudio signal using the second one or more parameter to enhance theloudness of the audio signal.

The mid-band frequency range may be 700 Hz and 4 kHz and the higher-bandfrequency range may be greater than 4 kHz.

Analysing the audio signal may comprise: determining a speech indicatorin metadata associated with the audio signal; and determining voiceactivity in the audio signal.

According to a second aspect there is provided an apparatus comprisingat least one processor and at least one memory including computer codefor one or more programs, the at least one memory and the computer codeconfigured to with the at least one processor cause the apparatus to atleast perform: analysing an audio signal comprises speech components;signal processing the audio signal using a first one or more parameterto enhance the speech component of the audio signal dependent ondetermining the audio signal comprises speech components; and signalprocessing the audio signal using a second one or more parameter toenhance the audio signal otherwise.

Signal processing the audio signal using a first one or more parameterto enhance the speech component of the audio signal dependent ondetermining the audio signal comprises speech components may cause theapparatus to perform: filtering the audio signal into at least twobands; performing a dynamic range control processing on the at least twobands according to the first one or more parameters, the first one ormore parameters being a first set of dynamic range control settings soto enhance an intelligibility of the speech component of the audiosignal; and combining the dynamic range control processed bands into anoutput audio signal.

Performing a dynamic range control processing on the at least two bandsmay cause the apparatus to perform compressing a mid-band frequencyrange compared to the higher-band frequency range.

Signal processing the audio signal using a first one or more parameterto enhance the speech component of the audio signal dependent ondetermining the audio signal comprises speech components may cause theapparatus to perform at least one of; equalising the audio signal toenhance an intelligibility of the speech component of the audio signal;and filtering the audio signal to enhance an intelligibility of thespeech component of the audio signal.

Signal processing the audio signal using the second one or moreparameter to enhance the audio signal may cause the apparatus toperform: filtering audio signal into at least two bands; performing adynamic range control processing on the audio signal at least two bandsaccording to the second one or more parameter, the second one or moreparameter being a second set of dynamic range control settings so toenhance a loudness of the audio signal; and combining the dynamic rangecontrol processed bands into an output audio signal.

Performing a dynamic range control processing on the audio signal atleast two bands according to a second set of dynamic range controlsettings may cause the apparatus to perform compressing a higher-bandfrequency range compared to the mid-band frequency range.

Signal processing the audio signal to enhance the loudness of the audiosignal may cause the apparatus to perform at least one of: equalisingthe audio signal using the second one or more parameter to enhance theloudness of the audio signal; and filtering the audio signal using thesecond one or more parameter to enhance the loudness of the audiosignal.

The mid-band frequency range may be 700 Hz and 4 kHz and the higher-bandfrequency range may be greater than 4 kHz.

Analysing the audio signal may cause the apparatus to perform:determining a speech indicator in metadata associated with the audiosignal; and determining voice activity in the audio signal.

According to a third aspect there is provided an apparatus comprising:an audio signal analyser configured to analyse an audio signal; an audiosignal processor configured to signal process the audio signal using afirst one or more parameter to enhance the speech component of the audiosignal dependent on determining the audio signal comprises speechcomponents; and signal processing the audio signal using a second one ormore parameter to enhance the audio signal otherwise.

The audio signal processor may comprise: a filter configured to filterthe audio signal into at least two bands; at least one dynamic rangecontroller configured to dynamic range control the at least two bandsaccording to the first one or more parameter, the first one or moreparameter being a first set of dynamic range control settings so toenhance an intelligibility of the speech component of the audio signal;and a combiner configured to combine the dynamic range control processedbands into an output audio signal.

The dynamic range controller may be configured to compress a mid-bandfrequency range compared to the higher-band frequency range.

The audio signal processor may comprise at least one of: an equaliserconfigured to equalise the audio signal to enhance an intelligibility ofthe speech component of the audio signal; and a filter configured tofilter the audio signal to enhance an intelligibility of the speechcomponent of the audio signal.

The audio signal processor may comprise: a filter configured to filteraudio signal into at least two bands; at least one dynamic rangecontroller configured to dynamic range control the audio signal at leasttwo bands according to the second one or more parameter, the second oneor more parameter being a second set of dynamic range control settingsso to enhance a loudness of the audio signal; and a combiner configuredto combine the dynamic range control processed bands into an outputaudio signal.

The dynamic range controller may be configured to compress a higher-bandfrequency range compared to the mid-band frequency range.

The audio signal processor may comprise at least one of: an equaliserusing the second one or more parameter configured to equalise the audiosignal to enhance the loudness of the audio signal; and a filter usingthe second one or more parameter configured to filter the audio signalto enhance the loudness of the audio signal.

The mid-band frequency range may be 700 Hz and 4 kHz and the higher-bandfrequency range may be greater than 4 kHz.

The audio signal analyser may comprise: a speech indicator determinerconfigured to determine a speech indicator in metadata associated withthe audio signal; and a voice activity determiner configured todetermine voice activity in the audio signal.

According to a fourth aspect there is provided an apparatus comprising:means for analysing an audio signal; means for signal processing using afirst one or more parameter the audio signal to enhance the speechcomponent of the audio signal dependent on determining the audio signalcomprises speech components; and means for signal processing the audiosignal using a second one or more parameter to enhance the audio signalotherwise.

The means for signal processing the audio signal using a first one ormore parameter to enhance the speech component of the audio signaldependent on determining the audio signal comprises speech componentsmay comprise: means for filtering the audio signal into at least twobands; means for performing a dynamic range control processing on the atleast two bands according to the first one or more parameter, the firstone or more parameter being a first set of dynamic range controlsettings so to enhance an intelligibility of the speech component of theaudio signal; and means for combining the dynamic range controlprocessed bands into an output audio signal.

The means for performing a dynamic range control processing on the atleast two bands may comprise means for compressing a mid-band frequencyrange compared to the higher-band frequency range.

The means for signal processing the audio signal using a first one ormore parameter to enhance the speech component of the audio signaldependent on determining the audio signal comprises speech componentsmay comprise at least one of: means for equalising the audio signalusing a first one or more parameter to enhance an intelligibility of thespeech component of the audio signal; and means for filtering the audiosignal using a first one or more parameter to enhance an intelligibilityof the speech component of the audio signal.

The means for signal processing the audio signal using the second one ormore parameter to enhance the audio signal may comprise: means forfiltering audio signal into at least two bands; means for performing adynamic range control processing on the audio signal at least two bandsaccording to the second one or more parameter, the second one or moreparameter being a second set of dynamic range control settings so toenhance a loudness of the audio signal; and means for combining thedynamic range control processed bands into an output audio signal.

The means for performing a dynamic range control processing on the audiosignal at least two bands according to a second set of dynamic rangecontrol settings may comprise means for compressing a higher-bandfrequency range compared to the mid-band frequency range.

The means for signal processing the audio signal using the second one ormore parameter to enhance the audio signal may comprise at least one of:means for equalising the audio signal using the second one or moreparameter to enhance the loudness of the audio signal; and means forfiltering the audio signal using the second one or more parameter toenhance the loudness of the audio signal.

The mid-band frequency range may be 700 Hz and 4 kHz and the higher-bandfrequency range may be greater than 4 kHz.

The means for analysing an audio signal may comprise: means fordetermining a speech indicator in metadata associated with the audiosignal; and means for determining voice activity in the audio signal.

An electronic device may comprise apparatus as described above.

A chipset may comprise apparatus as described above.

BRIEF DESCRIPTION OF DRAWINGS

For better understanding of the present invention, reference will now bemade by way of example to the accompanying drawings in which:

FIG. 1 shows schematically an electronic device employing someembodiments of the application;

FIG. 2 shows schematically an audio signal processor according to someembodiments;

FIG. 3 a shows schematically an example of an audio signal analyser asshown in FIG. 2 in further detail according to some embodiments;

FIG. 3 b shows schematically a further example of the audio signalanalyser as shown in FIG. 2 in further detail according to someembodiments;

FIG. 4 shows schematically the dynamic range controller as shown in FIG.2 in further detail according to some embodiments;

FIG. 5 shows schematically the operation of the audio signal analyser asshown in FIGS. 2, 3 a and 3 b according to some embodiments;

FIG. 6 shows schematically the operation of the dynamic range controlleras shown in FIGS. 2 and 4 according to some embodiments;

FIG. 7 shows an example of the dynamic range controller input to outputsettings for example frequency bands for speech or voice audio signalsaccording to some embodiments;

FIG. 8 shows an example of the dynamic range controller input to outputsettings for example frequency bands for music audio signals accordingto some embodiments;

FIG. 9 shows an example measured loudness difference between speech andmusic audio tuning according to some embodiments; and

FIG. 10 shows an example measured frequency response for speech andstandard tunings according to some embodiments.

DESCRIPTION OF SOME EMBODIMENTS OF THE APPLICATION

The following describes in more detail possible adaptive audio signalprocessing for use in speech or speech like audio for the provision ofhigher quality voice communication. In this regard reference is firstmade to FIG. 1 which shows a schematic block diagram of an exemplaryelectronic device or apparatus 10, which may incorporate an adaptivespeech enhancement signal processing apparatus according to embodimentsof the application.

The apparatus 10 may for example, as described herein be a mobileterminal or user equipment of a wireless communication system. In otherembodiments the apparatus 10 may be an audio-video device such as videocamera, a Television (TV) receiver, audio recorder or audio player suchas a mp3 recorder/player, a media recorder (also known as a mp4recorder/player), or any computer suitable for the processing of audiosignals.

The electronic device or apparatus 10 in some embodiments comprises amicrophone 11, which is linked via an analogue-to-digital converter(ADC) 14 to a processor 21. The processor 21 is further linked via adigital-to-analogue (DAC) converter 32 to loudspeakers 33. The processor21 is further linked to a transceiver (RX/TX) 13, to a user interface(UI) 15 and to a memory 22.

In some embodiments the apparatus 10 comprises a processor 21.Furthermore in some embodiments the apparatus 10 comprises a memory 22,and further a data storage section 24 and program code section 23. Theprocessor 21 can in some embodiments be configured to execute variousprogram codes. The implemented program codes in some embodimentscomprise adaptive speech enhancement signal processing code as describedherein. The implemented program codes 23 can in some embodiments bestored for example in the memory 22 for retrieval by the processor 21whenever needed. The memory 22 could further provide a section 24 forstoring data, for example data that has been encoded in accordance withthe application.

The adaptive speech enhancement signal processing code in someembodiments can be implemented in hardware or firmware.

In some embodiments the apparatus 10 comprises a user interface 15. Theuser interface 15 enables a user to input commands to the electronicdevice 10, for example via a keypad, and/or to obtain information fromthe electronic device 10, for example via a display. In some embodimentsa touch screen may provide both input and output functions for the userinterface. The apparatus 10 in some embodiments comprises a transceiver13 suitable for enabling communication with other apparatus, for examplevia a wireless communication network.

A user of the apparatus 10 for example can use the microphone 11 forinputting speech or other audio signals that are to be transmitted tosome other apparatus or that are to be stored in the data section 24 ofthe memory 22.

The analogue-to-digital converter (ADC) 14 in some embodiments convertsthe input analogue audio signal into a digital audio signal and providesthe digital audio signal to the processor 21. In some embodiments themicrophone 11 can comprise an integrated microphone and ADC function andprovide digital audio signals directly to the processor for processing.

The processor 21 in such embodiments then processes the digital audiosignal according to any suitable encoding process, for example asuitable adaptable multi-rate (AMR) coding or codec.

The resulting bit stream can in some embodiments be provided to thetransceiver 13 for transmission to another apparatus. Alternatively, thecoded audio data in some embodiments can be stored in the data section24 of the memory 22, for instance for a later transmission or for alater presentation by the same apparatus 10.

The apparatus 10 in some embodiments can also receive a bit stream withcorrespondingly encoded data from another apparatus via the transceiver13. In this example, the processor 21 may execute decoding program codestored in the memory 22. The processor 21 in such embodiments decodesthe received data. Furthermore the processor 21 in some embodiments canbe configured to apply adaptive speech enhancement audio signalprocessing as described herein, and provide the signal output to adigital-to-analogue converter 32. The digital-to-analogue converter 32converts the signal into analogue audio data and can in some embodimentsoutput the analogue audio via the loudspeakers 33. Execution of thedecoding and speech enhancement adaptive audio processing program codein some embodiments can be triggered by an application called by theuser via the user interface 15.

The received encoded data in some embodiments can also be stored insteadof an immediate presentation via the loudspeakers 33 in the data section24 of the memory 22, for instance for later decoding, speech enhancementadaptive audio signal processing and presentation or decoding andforwarding to still another apparatus.

It is to be understood again that the structure of the apparatus 10could be supplemented and varied in many ways.

It would be appreciated that the schematic structures described in FIGS.2, 3 a, 3 b, and 4 and the method steps shown in FIGS. 5 and 6 representonly a part of the operation of audio signal playback apparatus andspecifically adaptive audio signal processing apparatus or methods asexemplarily shown implemented in the apparatus shown in FIG. 1.

The concept of the application is to improve the intelligibility ofmobile phone speech or audio signal speech in general by implementingspeech enhancement adaptive audio signal processing.

In particular the concept of the application is to improve theperformance of loud speakers and transducers outputting speech audiosignals. It is understood that the structure of audio signals containingspeech is different from the audio signals containing music. Thedynamics of speech are higher than typically found in music. Furthermoresome parts of the audio spectrum for speech are not necessary in orderto make the speech audio signal understandable. Music however requires awider bandwidth in order to sound pleasant to the users ear.

Typically an electronic apparatus or device can have an audio outputdevice which attempts to maximise the loudspeaker output for music orspeech or attempts to find a compromise between the outputs. In theembodiments described herein an analyser attempts to analyse andrecognise speech in an audio signal and therefore determine whether theaudio signal contains speech (or for example is music). Depending on theanalysis speech enhancement can be performed. In the following examplesaudio signal processing dynamic range control (DRC) tuning is described.In such embodiments the analyser can be configured to determine DRCsettings which produce more efficient output of the audio signal. Itwould be understood that although the embodiments describe hereindiscuss speech enhancement audio signal processing dynamic range controlit would be understood that in some embodiments speech adaptiveequaliser or filters can be also implemented.

With respect to FIG. 2 the overview of the audio signal processoraccording to some embodiments is shown. In some embodiments the audiosignal processor comprises an audio signal analyser 101. The audiosignal analyser 101 is configured to receive the audio signal andanalyse the audio signal to determine whether or not the audio signal isspeech or non-speech (such as music) based. In some embodiments theaudio signal analyser 101 can output a set of parameters to control thespeech enhanced audio signal processing of the audio signal. Furthermorein some embodiments the audio signal analyser 101 outputs the analysisresult to the speech enhanced audio signal processor to be used to setthe parameters within the speech enhanced audio processor.

In some embodiments the audio signal analyser 101 outputs the results toa dynamic range controller 103.

In some embodiments the audio enhanced speech signal processor comprisesa dynamic range controller 103. The dynamic range controller 103 can beconfigured to receive the audio signal and also the output of the audiosignal analyser 101. The dynamic range controller 103 can be configuredto adaptively change the dynamic range controller processing of theaudio signal dependent on the output of the audio signal analyser 101.

The dynamic range controller 103 can then output the processed audiosignal to more efficiently drive the transducer.

With respect to FIGS. 3 a and 3 b examples of the audio signal analyser101 are shown in further detail. Furthermore with respect to FIG. 5 theoperation of the audio signal analyser 101 as shown in FIGS. 3 a and 3 bare shown in further detail according to some embodiments.

In some embodiments as shown in FIG. 3 a the audio signal analyser 101comprises a tag analyser 201. The tag analyser 201 is configured toreceive the audio signal to determine whether there is a music or speechtag associated with the audio signal.

The operation of inputting the audio signal to the speech analyser isshown in FIG. 5 by step 401.

In some embodiments the audio signal is associated with metadatacontaining tag or characteristic values identifying the audio as beingspeech or otherwise (such as music) in nature. In some embodiments theaudio signal analyser 101 receives the metadata but not the audio signalto be analysed by the tag analyser 201.

The tag analyser 201 can be configured to output the analysis of whetherthe input audio signal is music or speech audio to the DRC settingsgenerator 202.

The operation of analysing the audio signals for speech components isshown in FIG. 5 by step 403.

As shown in FIG. 3 b the audio signal analyser 101 can comprise a voiceactivity detector (VAD) 203. The voice activity detector 203 can be anysuitable voice activity detector configured to determine speech signals.

The audio signal analyser, in some embodiments as shown in both FIGS. 3a and 3 b, comprises a dynamic range controller (DRC) settings generator202. The DRC settings generator 202 is configured to receive the outputof the tag analyser 201, (or voice activity detector 203), or any othersuitable speech detection analysis output and generate a set of dynamicrange controller settings suitable for applying to the dynamic rangecontroller 103 dependent on the output of whether the audio signal isspeech or non-speech (such as music).

With respect to FIG. 7 an example set of dynamic range controllersettings are shown for speech tuning are shown. In the example shown inFIG. 7 there are a set of dynamic range control settings for variousfrequency bands which are passed to the dynamic range controller andapplied to each of the bands. With respect to FIG. 8 dynamic rangecontrol settings are shown for similar bands but where the audio signalis determined to be non-speech (for example music). The examples shownin FIGS. 7 and 8 show that in some embodiments for a speech audio signalthe dynamic range controller settings compress much more the mid-rangebetween 700 Hz and 4 kHz whereas for music only the higher frequenciesare compressed. In other words for low levels of signal there is a muchhigher compression factor. The impact of which when applied wouldenhance speech components within audio signals with speech componentsbut enhance the loudness of the audio signal otherwise.

With respect to FIG. 5 the operation of determining the DRC controlsettings dependent on whether the audio signal is speech (or voice) isshown in step 405.

Furthermore the DRC settings generator 202 can output the settings tothe dynamic range controller 103. The outputting of DRC settings to theDRC is shown in FIG. 5 by step 407.

With respect to FIG. 4 the dynamic range controller 103 according tosome embodiments is shown in further detail. Furthermore with respect toFIG. 6 the operation of the dynamic range controller 103 is described.

The dynamic range controller 103 can in some embodiments receive theinput audio signal.

The inputting of the audio signal is shown in FIG. 6 by step 501.

The dynamic range controller 103 in some embodiments can comprise asub-band filter 301 configured to filter the input audio signal into adetermined number of sub-bands. The sub-bands can be contiguous oroverlapping and be linear or non-linear in distribution or frequencyrange depending on the implementation embodiment. In the followingexamples the sub-band filter 301 can be configured to generate 5sub-bands for the audio signal, band 1 from 0-217 Hz, band 2 from217-727 Hz, band 3 from 727-1609 Hz, band 4 from 1609-4758 Hz, and band5 from 4758-24000 Hz. The sub-band filter can perform such filteringaccording to any suitable means.

The sub-band filter 301 can be configured to output each of thesub-bands to an associated band dynamic range controller. Thus in theembodiments as shown in FIG. 4 the first band, band 1, is passed to theband 1 DRC 303, the second band, band 2, is to passed to the band 2 DRC305 and the fifth band, band 5, passed to the band N DRC 307. It wouldbe understood that in some embodiments the number of sub-bands can begreater than or less than 5 (as represented by the value N).

The operation of filtering the audio into sub-bands is shown in FIG. 6by step 503.

In some embodiments the dynamic range controller 103 comprises a seriesof band dynamic range controllers. In the example shown in FIG. 4 thereis a band 1 dynamic range controller 303 configured to receive the band1 sub-band audio signal and the band 1 dynamic range control settingsfrom the analyser output, a band 2 dynamic range controller 305configured to receive the second band audio signals from the sub-bandfilter 301 and the dynamic range controller settings from the analyseroutput for the second band, and a band N dynamic range controller 307,where N=5 in this example, dynamic range controller configured toreceive the fifth band sub-band audio signal from the sub-band filter301 and the fifth band dynamic range controller settings from theanalyser output.

The operation of receiving the dynamic range controller settings fromthe analyser is shown in FIG. 6 by step 505.

Each of the band dynamic range controllers 303, 305 and 307 can beconfigured to receive the audio signal of the sub-band and apply thedynamic range control settings to each band to generate a dynamicallyrange controlled band output signal. The dynamically range controlledband output signals can be passed to a band combiner 309.

The operation of applying the dynamic range control settings to each ofthe sub-bands is shown in FIG. 6 by step 507.

In some embodiments the dynamic range controller 103 comprises a bandcombiner 309. The band combiner 309 can be configured to recombine thereceived band dynamically controlled signals to a single audio signal.

The combination of the dynamically range control band signals into asingle audio signal is shown in FIG. 6 by step 509.

Furthermore the band combiner 309 can be configured to output thedynamically range controlled band combined signals.

The operation of outputting the DRC signals is shown in FIG. 6 by step511.

In some embodiments the combiner can be configured to applyinterpolation on the audio signals such that where tuning sets arechanged there is no sudden change when the dynamic range controllerswitches between speech and non-speech audio signals. In someembodiments this dynamic switching DRC fading can be implemented withinthe band DRC components or in the DRC control settings components.

FIG. 9 shows an example measured the total loudness output differencebetween a speech tuned loudness 801 and a standard or conventionaltuning 803. In this example it is shown that the measured loudnessdifference is only 1.5 phon difference.

With respect to FIG. 10 an example measured frequency response betweenthe speech tuning and a conventional tuning is shown. With respect toFIG. 10 the frequency responses for speech tunings 903 and conventionaltuning 901 is shown where there is much more energy for lowerfrequencies and the frequency response is flatter with speech tunings.The reason for this is that with speech there is much less energy onlower frequencies and it can be compressed more than music. Furthermoreit would be understood that because the root mean squared (RMS) level ofspeech is smaller compared to the measurement signal used for thefrequency response measurements the difference in real life is greaterthan that seen in FIG. 10.

It would be understood that in some embodiments the voice activitydetector can be configured to determine an output such that where thereis uncertainty the voice activity detector outputs a non-voice ornon-speech result so that the detector does not determine music as beingspeech. This is because speech audio in the embodiments described hereinattempts to achieve the best loudness by driving the speaker as hard aspossible where speech audio is detected but avoid speaker damage asoperating with speech DRC settings at full volume may produce distortedsound.

Although the above examples describe embodiments of the applicationoperating within a codec within an apparatus 10, it would be appreciatedthat the invention as described below may be implemented as part of anyaudio (or speech) codec, including any variable rate/adaptive rate audio(or speech) codec. Thus, for example, embodiments of the application maybe implemented in an audio codec which may implement audio coding overfixed or wired communication paths.

Thus user equipment may comprise an audio codec such as those describedin embodiments of the application above.

It shall be appreciated that the term user equipment is intended tocover any suitable type of wireless user equipment, such as mobiletelephones, portable data processing devices or portable web browsers.

Furthermore elements of a public land mobile network (PLMN) may alsocomprise audio codecs as described above.

In general, the various embodiments of the application may beimplemented in hardware or special purpose circuits, software, logic orany combination thereof. For example, some aspects may be implemented inhardware, while other aspects may be implemented in firmware or softwarewhich may be executed by a controller, microprocessor or other computingdevice, although the invention is not limited thereto. While variousaspects of the application may be illustrated and described as blockdiagrams, flow charts, or using some other pictorial representation, itis well understood that these blocks, apparatus, systems, techniques ormethods described herein may be implemented in, as non-limitingexamples, hardware, software, firmware, special purpose circuits orlogic, general purpose hardware or controller or other computingdevices, or some combination thereof.

Thus at least some embodiments there may be an apparatus comprising atleast one processor and at least one memory including computer programcode the at least one memory and the computer program code configuredto, with the at least one processor, cause the apparatus at least toperform: analysing an audio signal; signal processing the audio signalto enhance the speech component of the audio signal dependent ondetermining the audio signal comprises speech components; and signalprocessing the audio signal to enhance a loudness of the audio signalotherwise.

The embodiments of this application may be implemented by computersoftware executable by a data processor of the mobile device, such as inthe processor entity, or by hardware, or by a combination of softwareand hardware. Further in this regard it should be noted that any blocksof the logic flow as in the Figures may represent program steps, orinterconnected logic circuits, blocks and functions, or a combination ofprogram steps and logic circuits, blocks and functions.

Thus at least some embodiments there may be a computer-readable mediumencoded with instructions that, when executed by a computer perform:analysing an audio signal comprises speech components; signal processingthe audio signal to enhance the speech component of the audio signaldependent on determining the audio signal comprises speech components;and signal processing the audio signal to enhance the loudness of theaudio signal otherwise

The memory may be of any type suitable to the local technicalenvironment and may be implemented using any suitable data storagetechnology, such as semiconductor-based memory devices, magnetic memorydevices and systems, optical memory devices and systems, fixed memoryand removable memory. The data processors may be of any type suitable tothe local technical environment, and may include one or more of generalpurpose computers, special purpose computers, microprocessors, digitalsignal processors (DSPs), application specific integrated circuits(ASIC), gate level circuits and processors based on multi-core processorarchitecture, as non-limiting examples.

Embodiments of the application may be practiced in various componentssuch as integrated circuit modules. The design of integrated circuits isby and large a highly automated process. Complex and powerful softwaretools are available for converting a logic level design into asemiconductor circuit design ready to be etched and formed on asemiconductor substrate.

Programs, such as those provided by Synopsys, Inc. of Mountain View,Calif. and Cadence Design, of San Jose, Calif. automatically routeconductors and locate components on a semiconductor chip using wellestablished rules of design as well as libraries of pre-stored designmodules. Once the design for a semiconductor circuit has been completed,the resultant design, in a standardized electronic format (e.g., Opus,GDSII, or the like) may be transmitted to a semiconductor fabricationfacility or “fab” for fabrication.

As used in this application, the term ‘circuitry’ refers to all of thefollowing:

-   -   (a) hardware-only circuit implementations (such as        implementations in only analog and/or digital circuitry) and    -   (b) to combinations of circuits and software (and/or firmware),        such as: (i) to a combination of processor(s) or (ii) to        portions of processor(s)/software (including digital signal        processor(s)), software, and memory(ies) that work together to        cause an apparatus, such as a mobile phone or server, to perform        various functions and    -   (c) to circuits, such as a microprocessor(s) or a portion of a        microprocessor(s), that require software or firmware for        operation, even if the software or firmware is not physically        present.

This definition of ‘circuitry’ applies to all uses of this term in thisapplication, including any claims. As a further example, as used in thisapplication, the term ‘circuitry’ would also cover an implementation ofmerely a processor (or multiple processors) or portion of a processorand its (or their) accompanying software and/or firmware. The term‘circuitry’ would also cover, for example and if applicable to theparticular claim element, a baseband integrated circuit or applicationsprocessor integrated circuit for a mobile phone or similar integratedcircuit in server, a cellular network device, or other network device.

The foregoing description has provided by way of exemplary andnon-limiting examples a full and informative description of theexemplary embodiment of this invention. However, various modificationsand adaptations may become apparent to those skilled in the relevantarts in view of the foregoing description, when read in conjunction withthe accompanying drawings and the appended claims. However, all such andsimilar modifications of the teachings of this invention will still fallwithin the scope of this invention as defined in the appended claims.

1-24. (canceled)
 25. A method comprising: analysing an audio signal ;signal processing the audio signal using a first one or more parameterto enhance the speech component of the audio signal dependent ondetermining the audio signal comprises speech components; and signalprocessing the audio signal using a second one or more parameter toenhance the audio signal otherwise.
 26. The method as claimed in claim25, wherein signal processing the audio signal using the first one ormore parameter to enhance the speech component of the audio signalcomprises: filtering the audio signal into at least two bands;performing a dynamic range control processing on the at least two bandsaccording to the first one or more parameter, the first one or moreparameter being a first set of dynamic range control settings so toenhance an intelligibility of the speech component of the audio signal;and combining the dynamic range control processed bands into an outputaudio signal.
 27. The method as claimed in claim 26, wherein performingthe dynamic range control processing on the at least two bands comprisescompressing a mid-band frequency range compared to the higher-bandfrequency range.
 28. The method as claimed in claim 25, wherein signalprocessing the audio signal using the first one or more parameter toenhance the speech component of the audio signal comprises at least oneof: equalising the audio signal using the first one or more parameter toenhance an intelligibility of the speech component of the audio signal;and filtering the audio signal using the first one or more parameter toenhance an intelligibility of the speech component of the audio signal.29. The method as claimed in claim 25, wherein signal processing theaudio signal using the second one or more parameter to enhance the audiosignal comprises at least one of: filtering the audio signal into atleast two bands; performing a dynamic range control processing on theaudio signal in at least two bands according to the second one or moreparameter, the second one or more parameter being a second set ofdynamic range control settings so as to enhance a loudness of the audiosignal; and combining the dynamic range control processed bands into anoutput audio signal.
 30. The method as claimed in claim 29, whereinperforming the dynamic range control processing on the audio signal inat least two bands according to the second set of dynamic range controlsettings comprises compressing a higher-band frequency range compared tothe mid-band frequency range.
 31. The method as claimed in claim 25,wherein signal processing the audio signal using the second one or moreparameter to enhance audio signal comprises at least one of: equalisingthe audio signal using the second one or more parameter to enhance theloudness of the audio signal; and filtering the audio signal using thesecond one or more parameter to enhance the loudness of the audiosignal.
 32. The method as claimed in claim 27, wherein the mid-bandfrequency range is 700 Hz and 4 kHz and the higher-band frequency rangeis greater than 4 kHz.
 33. The method as claimed in claim 25, whereinanalysing the audio signal comprises: determining a speech indicator inmetadata associated with the audio signal; and determining voiceactivity in the audio signal.
 34. An apparatus comprising at least oneprocessor and at least one memory including computer code for one ormore programs, the at least one memory and the computer code configuredto with the at least one processor causes the apparatus to at least:analyse an audio signal; signal process the audio signal using a firstone or more parameter to enhance the speech component of the audiosignal dependent on determining the audio signal comprises speechcomponents; and signal process the audio signal using a second one ormore parameter to enhance the audio signal otherwise.
 35. The apparatusas claimed in claim 34, wherein the signal processed audio signal usingthe first one or more parameters to enhance the speech component of theaudio signal causes the apparatus to at least one of: filter the audiosignal into at least two bands; perform a dynamic range controlprocessing on the at least two bands according to the first one or moreparameters, the first one or more parameters being a first set ofdynamic range control settings so to enhance an intelligibility of thespeech component of the audio signal; and combine the dynamic rangecontrol processed bands into an output audio signal.
 36. The apparatusas claimed in claim 35, wherein the dynamic range control processingcauses the apparatus to compress a mid-band frequency range compared tothe higher-band frequency range.
 37. The apparatus as claimed in claim34, wherein the signal processed audio signal using the second one ormore parameter causes the apparatus to at least one of: filter the audiosignal into at least two bands; perform a dynamic range controlprocessing on the audio signal in at least two bands according to thesecond one or more parameter, the second one or more parameter being asecond set of dynamic range control settings so to enhance a loudness ofthe audio signal; and combine the dynamic range control processed bandsinto an output audio signal.
 38. The apparatus as claimed in claim 37,wherein the dynamic range control processing on the audio signal causesthe apparatus to compress a higher-band frequency range compared to themid-band frequency range.
 39. The apparatus as claimed in claim 34,wherein when the audio signal comprises speech components, the apparatusis caused to: determine a speech indicator in metadata associated withthe audio signal; and determine voice activity in the audio signal. 40.An apparatus comprising: an audio signal analyser configured to analysean audio signal; an audio signal processor configured to signal processthe audio signal using a first one or more parameter to enhance thespeech component of the audio signal dependent on determining the audiosignal comprises speech components; and signal processing the audiosignal using a second one or more parameter to enhance the audio signalotherwise.
 41. The apparatus as claimed in claim 40, wherein the audiosignal processor comprises at least one of: a filter configured tofilter the audio signal into at least two bands; at least one dynamicrange controller configured to dynamic range control the at least twobands according to the first one or more parameter, the first one ormore parameter being a first set of dynamic range control settings so asto enhance an intelligibility of the speech component of the audiosignal; and a combiner configured to combine the dynamic range controlprocessed bands into an output audio signal.
 42. The apparatus asclaimed in claim 41, wherein the dynamic range controller is configuredto compress a mid-band frequency range compared to the higher-bandfrequency range.
 43. The apparatus as claimed in claim 40, wherein theaudio signal processor comprises at least one of: a filter configured tofilter audio signal into at least two bands; at least one dynamic rangecontroller configured to dynamic range control the audio signal at leasttwo bands according to the second one or more parameter, the second oneor more parameter being a second set of dynamic range control settingsso to enhance an intelligibility of the speech component of the audiosignal; and a combiner configured to combine the dynamic range controlprocessed bands into an output audio signal.
 44. The apparatus asclaimed in claim 40, wherein the audio signal analyser comprises: aspeech indicator determiner configured to determine a speech indicatorin metadata associated with the audio signal; and a voice activitydeterminer configured to determine voice activity in the audio signal.